Saw-mill dog



(No Model.)

2 SheetsShet 1.

WLM. WILKIN..

SAW MILL DOG.

Patentd Mar. 4, 1884..

' Inventor. 71"772 .MZkin (Fara;

N. rmns Prwwum m. wnhin mn. n. c.

I UNITED STATES ATENT Fries.

XVILLIAM \VILKIN, OF EAST SAGINAVV, MICHIGAN.

SAW-MILL DOG.

SPECIFICATION forming part of Letters Patent No. 294,710, dated March 4,1884.

Application filed March 1, 1882. Renewed January 14, 1884. (No model.)

' to whom it may concern.-

Be it known that I, WILLIAM M. WILKIN,

a citizen of the United States, residing at East Saginaw, in the countyof Saginaw, in the State of Michigan, have invented new and usefulImprovements in Saw-Mill Dogging Apparatus; and I do hereby declare thatthe following is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings and the letters or figures ofreference marked thereon. i

In the operation of a saw-mill, the dogging apparatus is employed tofirmly hold the log to the jacks or knees, which push it toward the saw,and after the log is squared up into a cant the dogs hold it against theknees until thelast out is made.

The requirements for properly holding a log are entirely different fromthose for holding a cant or board, and therefore a mill is generallyprovided with two different apparatuses, one of which is called alog-dog and the other a board-dog.

Various attempts-have been made to pro- .vide an apparatus which willserve equally well for both purposes, but none that I am aware of haveproved entirely successful. To.

accomplish this end is the primary object of this invention.

To properly grasp and hold a log, the dogs should grasp it wellbelow andwell above the central horizontal line, for the reason that during theoperation of pushing the log forward,. and when the carriage is suddenlystopped or started, the log is apt to turn, and if the dogs only reach ashort distance from the face of the knee, although they may enter 'fromabove and below the center line, they will not have a hold withsufficient purchase to properly holdthe log from turning. It is furtheressential that the dogs be so arranged and operated that they will grasplogs of various sizes in the manner above described with the sameeffect. The dogs should also be capable of reaching out and graspinglogs or cantswhich are not snug against the knee, and draw them up snug.When used for holding a cant, the dogs should extend very little beyondthe knee-line, so as not to be in the way of the saw when sawing thelast out. Besides the above requirements, the dogs should be capable ofinstant adjustment from one capacity to another,

and thisadjustment should be effected by the movement of not more thantwo lovers; and, further, the dogs should be able to grasp the log orcant with great force, so as to thoroughly embed the bits, and thisforce'should be ob tained without undue exertion by the attendant.

To grasp logs with equal effect both above and below the centralhorizontal line, I provide two dog-bits, oneof which works down-- wardand the'other upward at the same time and by the same operatingmechanism. These two bits have long shanks, and are pivoted together atthe ends of the shanks, and are also pivoted near the bits to arms whichextend back to the rear of the knee, and are there pivoted together upona common center. The dogs are not attached to the standard of the knee,and therefore they can move with a great degree of latitude. Theirgeneral design is that of a pair of grapplers, and as they move from acommon center they can grasp logs above and below the central line innearly the same position on the log, no matter where, by the size of thelog, the central line cuts the standard. The point where the arms towhich the dogs are attached is pivoted I make movable horizontally, andthereby I am able to extend the dogs far beyond the face of the knee ordraw them back, so as to extend a very little beyond the knee line. Tothis movable pivot I attach a lever, by which I can moveit, and therebyI can send the dogs out and grasp a log or cant and draw it back againstthe face of the knee. One of the dogshanks I provide with a lever, bywhich I move them into and out of the timber. The arms to which thedogsarcpivoted I make of springs, or provide them with springs, andthereby I obtain a force outside of the attendant for forcing the dogsinto the timber.

I have also devised several modifications of the above construction,some of which show all and some only a part of the above features.

In order to enable others skilled in the art to which this inventionrelates to construct the same, I will proceed to minutely describe thesame, together with the aforesaid modifi- IOC paratus possessing all thefeatures above described. Fig. 2 is a front elevation of the same. Figs.3, 4-, 5 are modifications, which will be fully pointed out hereinafter.Fig. (3 is a front view of the parts shown in Fig. 5. .Fig. 7 is adetail of construction ofparts shown in Figs. 5 and (3.

The device shown in Fig. l is as follows:

A is the knee of the head-block.

.3 is the block.

0 is the log.

I) D are the dogs, which are pivoted together at (I, and at d (1 theyare pivoted upon the spring-arms E E.

F is the lever attached to the dog 1).

E is the point at which the arms E E are attached and pivoted. Thispoint is ablock with a wrist-pin or pivot, and is mounted in grooves ina standard, A, extending from the knee A.

Gis thelever by which this block E is moved.

On the right of Fig. 2 is shown a yoke or frame, II, which is attachedto the side of the knee. This serves as a guide or case to hold thedogs, and yet allow them free action. In place of this case H, the kneemay be provided with a central slot or opening to receive the dogs. Thetwo shanks at d are connected with ajoint somewhat like that in a rule.It is so formedthat the dogs can only openjust far enough to let thepivot d pass beyond the line of the pivots d" (1; hence when the dogsare opened fully they will stay open until the pivot d is drawn backpast the line. XVhen this occurs, the spring-arms E will throw the dogsinto the log. This manner of constructing the joint (Z saves thenecessity of a catch to hold the lever F down, and thus keep the dogsopen. 0 is a clamp on the springs for regulating their tension.

The operation of this device is as follows: The attendant raises the endof lever F far enough to throw the pivot (I back of the cen tral linebetween the pivots d d. The springs E E then act upon the dogssimultaneously and throw them into the log. The dog D, when the log isso small that its central line comes below the pivot d, enters the logfirst, and the other quickly follows; but to do so the arms have movedslightly on their pivot E. The log is now thoroughly grasped by thedogs, as seen by dotted lines in Fig. 1. If the log is not snug againstthe knee, it can be drawn up by the lever G. If it was a cant that wasto be grasped in place of a log, the attendant would, before springingthe dogs, move the lever G- back, so as to draw back the dogs so theywould just nip onto the edge of the cant. .ly the use of the two loversG and F the attendant can adjust and operate the dogs at will.

The modified constructions shown are as fol lows:

In Fig. 3 only one dog is used, I), which is pivoted at (Z to a link, 1)which, in place of carrying a lower dog, is pivoted to the knee offrame-work at d". Only one spring-bar, E", is used, and this is not aspring of itself, as they are in Fig. 1, but is connected with awhip-spring, E The bar E is pivoted to a stationary point at the rear ofthe knee.

The construction shown in Iliig. .4: is very similar to that in Fig. 1.It shows another method of constructing the spring-barsviz., using barsE, as in Fig. 3, and connecting thereto a spring, E, for operating thedogs. In this construction the bars are not pivoted to a common center.It is not necessary that they be pivoted to a common. center. Thefarther the centers are apart vertically the nearer will the dogs moveto the face of the knee as they approach each other.

Figs. and 6 show the spring-bars in use upon common board-dogs whichmove in a direct vertical line. This construction is as follows: D I)are the dogs, which are mounted in clips 1) D, which slide upon thevertical bar a. The dogs, or rather the clips, are connected by links I)D, which are pivoted together at d, the same as the shanks of the dog I)D in Fig. 1, and one of them is provided with a lever, F. These linksoperate the same as the shanks of the toggles in Fig. 1. The spring-barpivot is in a slot at the point of its connection with the knee, so asto allow the dogs to move in adirect vertical line. This construction isonly serviceable as a board-dog.

Fig. '7 shows how the dog I) is adjusted in the clip I). It is mountedin a socket, and has a spring, S, to keep it out in place. If a largelog is rolled upon the blocks, the dog will be pressed back into thesocket, overcoming the spring.

By having the dogging apparatus connected with a sliding pivot or blockback of the standard and moved by a lever, which, as shown in Fig. 1, isprovided with means for stopping it and holding it at various points,the log can be thrown out from the knee to a desirable distance and heldthere, thus serving the purpose of an independent knee in holdingtapering logs or sawing tapering stuff.

\Vhat I claim as new is- 1. In a saw-mill dogging apparatus, thecombination, substantially as shown, of the following elements: two dogsadapted to grasp the log or cant from opposite directions,which areindependent of the knee, and are pivoted I together by their shanks, andare also pivoted near their hits to bars which are pivoted to a supportupon the knee back of the standard.

2. In a saw-mill dogging apparatus, the combination, substantial] y asshown, of the following elements: two dogs adapted to grasp the log orcant in opposite directions, which are pivoted together by their shanks,and are also pivoted near their bits to spring-bars which are pivoted toa support upon theknee back of the standard.

3. The combination, with the knee or jack ofa saw-mill head-block, of adogging apparatus which has-its attachment to said jack upon alaterally-movable support back of the standard, and is yoked at itsforward end'loosely within a frame formed by or uponsaid standard, andis-provided with means, substantially as shown, whereby the attendantcan move the same laterally upon the jack and extend the bits of thedogs more or less beyond the face of the standard, for the purposesmentioned.

4. 111 a saw-mill (logging apparatus, the combination,substantially asshown,of the following elements: two dogs adapted to grasp the log orcant in opposite directions, which are pivoted together at their shanks,and are also pivoted near their bits to bars which are pivoted upon asliding pivot on the knee back of the standard, which sliding pivot isprovided with means whereby the attendant can move the same to and froalt-pleasure, whereby the said dogging apparatus can be adjusted by theattendant so as to cause the dogs to act at a greater or less distancefrom the face of the knee, and also whereby the attendant can grapple alog or cant n'ot snug against the knee and draw it back against the faceof the knee.

nected with the knee back of the standard, and

extending to near the face of the knee, and there connected with a dogwhich is pivoted thereto near its bit, and is operated upon by atoggle-lever.

6. In a saw-mill dogging apparatus wherein the dog-bits are pivoted onthe ends of springbars which are pivotally connected with the knee backof the standard, and are moved from contact with the log or cant by atogglelever, the combination, with said toggles,of a stop for limitingthe movement of the same at the joint toward the face of the head-blockstandard, substantially as and for the purposes set forth.

In testimony that I claim the foregoing I have hereunto set my hand this21st day of February, 1882.

\VM. M. IVILKIN.

